If someone falls off the ladder and gets seriously hurt, you’d better leave him _____ he falls and try to get help.
Mr. Wang was such a good teacher _______ the students love and respect.
Until the present century, ________ demand for natural gas.
By the end of this year, we _____ 2000 English words.
_______ knows the truth will tell you about it , I think .
The head engineer is in ________ the project .